#include <iostream>
#include <cstring>
#include <algorithm>
#include <cstdio>
#include <cmath>
#include <vector>
#include <list>
#include <queue>
#include <stack>
#include <map>
#include <unordered_map>
#include <unordered_set>
#include <set>
#include <bitset>
#include <utility>
using namespace std;

#define mm(a, n) memset(a, n, sizeof a)
#define mk(a, b) make_pair(a, b)

const double eps = 1e-6;
const int INF = 0x3f3f3f3f;

typedef long long LL;
typedef unsigned long long ULL;
typedef pair<int, int> PII;
typedef pair<double, double> PDD;
typedef pair<LL, LL> PLL;
typedef pair<int, LL> PIL;

inline void quickread() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
}

int n;

inline void solution() {
    string s;
    cin >> n >> s;
    unordered_set<char> st;
    for (auto & c : s) st.insert(c);

    int l = 0, r = 0;
    for (int i = 1; i < s.size(); i ++ ) {
        if (s[i] == s[i - 1]) {
            r ++;
        } else {
            if ((r - l + 1) % n != 0) 
                st.erase(s[i - 1]);
            l = r;
        }
    }
    if ((r - l + 1) % n != 0) 
        st.erase(s[i - 1]);
    string res = "";
    unordered_map<char, bool> mp;
    for (int i = 0; i < s.size(); i ++ ) {
        if (st.find(s[i]) == st.end()) res += s[i];
        else {
            if (mp[s[i]] == false) {
                cout << s[i];
                mp[s[i]] = true;
            }
            res += s[i];
            i += n - 1;
        }
    }
    cout << endl << res << endl;
}

int main() {
    freopen("input.txt", "r", stdin);
    quickread();
    solution();
    return 0;
}